Notice broken sessions in the bar, and offer to repair them there

Nothing tells you a session is unresumable until you try to resume it, and by
then you have usually forgotten which one it was. The widget now scans every
project on a timer and whenever the panel opens, marks its icon when something
needs fixing, and lists the affected sessions with a repair button that says
what it will drop and what it will keep before doing anything.

The scan had to get roughly eighty times cheaper first. Classifying a transcript
needs two facts - what its last message id is, and whether any Anthropic id
exists at all - and the first settles the common case alone. Reading the tail of
each file and only opening the whole thing when the tail already looks wrong
takes the sweep from ~5s to ~60ms across 59 transcripts, which is the difference
between something that can sit on a timer and something that cannot. `--all`
uses the same path, and `--json` exposes it.

The badge is a dot beside the mark rather than a recolouring of it: this widget's
job is to report which provider is active, and tinting it red to mean something
else entirely would be a lie about that.

Verified by planting a genuinely corrupted transcript, watching the scan find it
and the dot appear, then removing it and watching both clear.

omarchy/smoido.claude-mode/BarWidget.qml

@@ -63,6 +63,15 @@ BarWidget {
   // bar stays quiet exactly when nothing unusual is configured.
   readonly property bool gateway: known && mode !== "anthropic"
 
+  readonly property color urgentColor: {
+    var c = Color.urgent
+    var mx = Math.max(c.r, c.g, c.b)
+    var mn = Math.min(c.r, c.g, c.b)
+    var l = (mx + mn) / 2
+    var d = 1 - Math.abs(2 * l - 1)
+    return (d > 0.0001 ? (mx - mn) / d : 0) >= 0.15 ? c : "#d2685f"
+  }
+
   readonly property color activeColor: !known
     ? Color.muted
     : (gateway ? Color.accent : (bar ? bar.barForeground : Color.foreground))
@@ -111,10 +120,48 @@ BarWidget {
     running: false
   }
 
+  // ---- Broken transcripts
+  //
+  // A session cut short by a mode switch cannot be resumed, and nothing tells
+  // you until you try - by which time you have usually forgotten which session
+  // it was. So the bar checks periodically and marks itself when there is
+  // something to fix.
+  //
+  // The scan reads the tail of each transcript first and only opens the whole
+  // file when the tail already looks wrong, which is what makes it cheap enough
+  // to sit on a timer: ~60ms for 59 transcripts here, against 5s for the naive
+  // version that read every byte of every one.
+  property var brokenSessions: []
+
+  Process {
+    id: scanProc
+    running: false
+    command: [root.cmRoot + "/bin/claude-mode", "repair-session", "--json"]
+    stdout: StdioCollector {
+      waitForEnd: true
+      onStreamFinished: {
+        var d = null
+        try { d = JSON.parse(String(text || "")) } catch (e) { d = null }
+        root.brokenSessions = (d && d.broken) ? d.broken : []
+      }
+    }
+  }
+
+  function scanSessions() { if (!scanProc.running) scanProc.running = true }
+
+  Timer {
+    interval: 20 * 60 * 1000
+    running: true
+    repeat: true
+    triggeredOnStart: true
+    onTriggered: root.scanSessions()
+  }
+
   function refresh() {
     healthFile.reload()
     stateFile.reload()
     if (!root.health) seedProc.running = true
+    root.scanSessions()
   }
 
   Component.onCompleted: Qt.callLater(root.refresh)
@@ -134,14 +181,34 @@ BarWidget {
     anchors.centerIn: parent
     spacing: root.gap
 
-    BrandIcon {
-      id: icon
+    Item {
       anchors.verticalCenter: parent.verticalCenter
+      width: icon.width
+      height: icon.height
       visible: root.logo !== ""
-      pathData: root.logo
-      opticalScale: Modes.logoScale(root.mode)
-      color: root.activeColor
-      iconSize: root.iconPx
+
+      BrandIcon {
+        id: icon
+        anchors.fill: parent
+        pathData: root.logo
+        opticalScale: Modes.logoScale(root.mode)
+        color: root.activeColor
+        iconSize: root.iconPx
+      }
+
+      // Recolouring the mark would misreport the mode, which is this widget's
+      // whole job, so the warning gets its own dot instead.
+      Rectangle {
+        visible: root.brokenSessions.length > 0
+        width: Math.max(4, Math.round(root.iconPx / 3.2))
+        height: width
+        radius: width / 2
+        color: root.urgentColor
+        anchors.right: parent.right
+        anchors.top: parent.top
+        anchors.rightMargin: -Math.round(width / 3)
+        anchors.topMargin: -Math.round(width / 4)
+      }
     }
 
     // Only reached when claude-mode is not installed - there is no brand to
@@ -185,6 +252,11 @@ BarWidget {
     var models = root.health && root.health.models ? root.health.models : null
     if (models && models.opus) lines.push("opus " + models.opus)
     if (models && models.sonnet) lines.push("sonnet " + models.sonnet)
+    if (root.brokenSessions.length > 0) {
+      lines.push(root.brokenSessions.length === 1
+        ? "1 session needs repair"
+        : root.brokenSessions.length + " sessions need repair")
+    }
     return lines.join("  ·  ")
   }
 
@@ -199,6 +271,7 @@ BarWidget {
   }
 
   onHealthChanged: syncTooltip()
+  onBrokenSessionsChanged: syncTooltip()
 
   // Hover must come from a HoverHandler: once triggerPress() exists the bar's
   // own slot MouseArea accepts hover events and swallows them before any